The usual period of inspection (with some exceptions) is one year. Few around the world sailors do that. If you don't carry the raft in a hard case and protect it from the elements (like it would be in an deck mounted soft case, or even one crammed in a locker), then I wouldn't be counting on it.

We have ours done regularly on a yearly schedule -- unless we're not going offshore. It's in a hard case under a sunbrella cover. The case looks like it is new. The group we use packs commercial, military, and passenger vessels -- as well as "pleasure" craft.

As for packing it yourself, there's a proceedure for pressure testing the vessel periodically which requires some equipment; you need to inflate the raft (WITHOUT USING THE EXPLOSIVE force of the emergency inflator) and check the seams for leaks over a couple of days or so. Even then, you need to visually inspect the seams carefully because when the inflator goes off, it's very tough. Packing your own chute, like most things: Might make sense IF you really know what you're doing. (It doesn't meet USCG certification requirements. I understand that you are not required to have a raft; however, if you do, then you must have it inspected and certified by a recognized firm & have papers to show it. You're not likely to get tagged if you don't have passengers, or unless you piss someone off who's boarded you.)

As for carrying a dingy on deck, unless you have a very large boat, I'd not do it in a passage making situation -- but that's my preference. If you're rigging a chute, changing sails, using a staysail, etc.-- I'd find it more of burden and safety issue. But, Dan might point-out, in this case maybe it might have helped :^)))).